The use of control apparatus in processes for the production of treated materials has become more and more widespread in recent years. High costs of labor, increased incidences of decreased quality and the need for more uniformity in products have been the prime motivating forces behind the switch over.
In the treating of materials, e.g. the coating, impregnation etc. and drying of materials such as paper, cloth etc. it has especially become increasingly desirable to utilize a fully automatic process and U.S. Pat. No. 3,596,071 is directed to a system which approaches such a realization. This patent discloses and claims a method and apparatus for the control of a coater and dryer wherein variables such as moisture content, resins solids concentration, percent resin and percent volatiles are measured and/or computed according to various mathematical formulae. The computed values are then used to control the rate of resins application and the drying rate of the treated material. The controls effected by the patentee are of the conventional feedback type. Analog computers and controllers are utilized to adjust the applicator roll speed, based on the percent resins solids calculation deviation from set point.
The patentee, however, does not provide means for automatically adjusting the roll gaps of the reverse roll applicator in conjunction with applicator roll speed changes and therefore resin consumption remains relatively high and/or filler and laminate quality is substantially lower than would be preferred.